From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on archive.lwn.net X-Spam-Level: X-Spam-Status: No, score=-5.8 required=5.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=unavailable autolearn_force=no version=3.4.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by archive.lwn.net (Postfix) with ESMTP id 595807DD31 for ; Thu, 19 Apr 2018 13:48:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752100AbeDSNsO (ORCPT ); Thu, 19 Apr 2018 09:48:14 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:43868 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752710AbeDSNrR (ORCPT ); Thu, 19 Apr 2018 09:47:17 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 3598D406803E; Thu, 19 Apr 2018 13:47:17 +0000 (UTC) Received: from llong.com (dhcp-17-164.bos.redhat.com [10.18.17.164]) by smtp.corp.redhat.com (Postfix) with ESMTP id 940E7215CDA7; Thu, 19 Apr 2018 13:47:16 +0000 (UTC) From: Waiman Long To: Tejun Heo , Li Zefan , Johannes Weiner , Peter Zijlstra , Ingo Molnar Cc: cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, kernel-team@fb.com, pjt@google.com, luto@amacapital.net, Mike Galbraith , torvalds@linux-foundation.org, Roman Gushchin , Juri Lelli , Waiman Long Subject: [PATCH v7 5/5] cpuset: Make generate_sched_domains() recognize isolated_cpus Date: Thu, 19 Apr 2018 09:47:04 -0400 Message-Id: <1524145624-23655-6-git-send-email-longman@redhat.com> In-Reply-To: <1524145624-23655-1-git-send-email-longman@redhat.com> References: <1524145624-23655-1-git-send-email-longman@redhat.com> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.5]); Thu, 19 Apr 2018 13:47:17 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.5]); Thu, 19 Apr 2018 13:47:17 +0000 (UTC) for IP:'10.11.54.6' DOMAIN:'int-mx06.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'longman@redhat.com' RCPT:'' Sender: linux-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org The generate_sched_domains() function and the hotplug code are modified to make them use the newly introduced isolated_cpus mask for schedule domains generation. Signed-off-by: Waiman Long --- kernel/cgroup/cpuset.c | 35 +++++++++++++++++++++++++++++++++-- 1 file changed, 33 insertions(+), 2 deletions(-) diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c index d05c4c8..a67c77a 100644 --- a/kernel/cgroup/cpuset.c +++ b/kernel/cgroup/cpuset.c @@ -683,13 +683,14 @@ static int generate_sched_domains(cpumask_var_t **domains, int ndoms = 0; /* number of sched domains in result */ int nslot; /* next empty doms[] struct cpumask slot */ struct cgroup_subsys_state *pos_css; + bool root_load_balance = is_sched_load_balance(&top_cpuset); doms = NULL; dattr = NULL; csa = NULL; /* Special case for the 99% of systems with one, full, sched domain */ - if (is_sched_load_balance(&top_cpuset)) { + if (root_load_balance && !top_cpuset.isolation_count) { ndoms = 1; doms = alloc_sched_domains(ndoms); if (!doms) @@ -712,6 +713,8 @@ static int generate_sched_domains(cpumask_var_t **domains, csn = 0; rcu_read_lock(); + if (root_load_balance) + csa[csn++] = &top_cpuset; cpuset_for_each_descendant_pre(cp, pos_css, &top_cpuset) { if (cp == &top_cpuset) continue; @@ -722,6 +725,9 @@ static int generate_sched_domains(cpumask_var_t **domains, * parent's cpus, so just skip them, and then we call * update_domain_attr_tree() to calc relax_domain_level of * the corresponding sched domain. + * + * If root is load-balancing, we can skip @cp if it + * is a subset of the root's effective_cpus. */ if (!cpumask_empty(cp->cpus_allowed) && !(is_sched_load_balance(cp) && @@ -729,6 +735,10 @@ static int generate_sched_domains(cpumask_var_t **domains, housekeeping_cpumask(HK_FLAG_DOMAIN)))) continue; + if (root_load_balance && + cpumask_subset(cp->cpus_allowed, top_cpuset.effective_cpus)) + continue; + if (is_sched_load_balance(cp)) csa[csn++] = cp; @@ -820,6 +830,12 @@ static int generate_sched_domains(cpumask_var_t **domains, } BUG_ON(nslot != ndoms); +#ifdef CONFIG_DEBUG_KERNEL + for (i = 0; i < ndoms; i++) + pr_info("rebuild_sched_domains dom %d: %*pbl\n", i, + cpumask_pr_args(doms[i])); +#endif + done: kfree(csa); @@ -860,7 +876,12 @@ static void rebuild_sched_domains_locked(void) * passing doms with offlined cpu to partition_sched_domains(). * Anyways, hotplug work item will rebuild sched domains. */ - if (!cpumask_equal(top_cpuset.effective_cpus, cpu_active_mask)) + if (!top_cpuset.isolation_count && + !cpumask_equal(top_cpuset.effective_cpus, cpu_active_mask)) + goto out; + + if (top_cpuset.isolation_count && + !cpumask_subset(top_cpuset.effective_cpus, cpu_active_mask)) goto out; /* Generate domain masks and attrs */ @@ -1102,6 +1123,7 @@ static int update_isolated_cpumask(const char *buf) top_cpuset.isolation_count = cpumask_weight(top_cpuset.isolated_cpus); spin_unlock_irq(&callback_lock); + rebuild_sched_domains_locked(); out_ok: retval = 0; @@ -2530,6 +2552,11 @@ static void cpuset_hotplug_workfn(struct work_struct *work) cpumask_copy(&new_cpus, cpu_active_mask); new_mems = node_states[N_MEMORY]; + /* + * If isolated_cpus is populated, it is likely that the check below + * will produce a false positive on cpus_updated when the cpu list + * isn't changed. It is extra work, but it is better to be safe. + */ cpus_updated = !cpumask_equal(top_cpuset.effective_cpus, &new_cpus); mems_updated = !nodes_equal(top_cpuset.effective_mems, new_mems); @@ -2538,6 +2565,10 @@ static void cpuset_hotplug_workfn(struct work_struct *work) spin_lock_irq(&callback_lock); if (!on_dfl) cpumask_copy(top_cpuset.cpus_allowed, &new_cpus); + + if (top_cpuset.isolation_count) + cpumask_andnot(&new_cpus, &new_cpus, + top_cpuset.isolated_cpus); cpumask_copy(top_cpuset.effective_cpus, &new_cpus); spin_unlock_irq(&callback_lock); /* we don't mess with cpumasks of tasks in top_cpuset */ -- 1.8.3.1 -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html